[sombragris]

Not necessarily my experience. I wrote (and I am writing) several academic documents with it. There are its quirks, of course, but with good classes such as memoir, I don't feel the need to do a lot more than basic customization in the preamble. Still is a good tool for me.

[eddieh]

For me the memoir class made LaTeX worse. The titlesec package is more customizable, easier to use, and reduced the size of the preamble significantly.

[sombragris]

That's if you need to customize headings. I usually can keep using the standard ones, so that's not my case, and I suspect this also applies to a lot of people.

[eddieh]

Customizing chapter styles, page styles, and headings was my sole reason for using the memoir class. I'm probably in the minority, that's true.